Upper body strength questions....

I apologize if this is sort of off topic from running. My arms/shoulders/chest/upper back look toned from weight conditioning, but I hate doing pushups and can't do more than 2 pullups at a time. I'm trying to strengthen this area for mud run obstacles. Can anyone give me some direction in how many I should be aiming for each week? All of the women I know who do pullups with ease have been doing them for over a decade. How do I get there and how long will it take?